The main objectives of the proposed research are: 1) to characterize the association between Electronic Fetal Minotoring and the Apgar Score, controlling for confounding factors; 2) identify subgroups, if any, in which monitoring has a particularly strong or weak effect; 3) to develop a statistical risk function for predicting the Apgar Score. Between 1970 and 1975, some 16,000 deliveries occurred at the Beth Israel Hospital in Boston. Complete information on Electronic Fetal Monitoring, the Apgar Score, and a number of demographic and clinical factors were collected, edited and entered into a computer data base. It is the largest one of this kind, and has already been used to assess the relationship of Electronic Fetal Monitoring to neo-natal death and to the cesarean section rate. We propose to carry out a careful multi-variate analysis of the data, to tease out the association between Electronic Fetal Monitoring and the Apgar Score while controlling for confounding variables. To accomplish this, we intend to use logistic regression, log linear models and stratification of a confounder score.